Google Nest: Unknown error talking to Cloud Pub/Sub, see logs

I’m receiving an unknown error when trying to connect Google nest for the first time.

I followed the outlined steps and created a cloud project on my Google Workspace account. I then gave permission via my personal Google account which is the one tied to my Google Nest devices. Initially it had an error communicating with the Google Cloud project because the permissions were set to internal, I changed to external and that seemed to resolve it.

Now when adding Nest I:

  1. Add my Google Cloud project ID
  2. Add my Device Access Project ID
  3. Grant authorisation to the devices via personal Google account
  4. Pass through the security warning ‘Google hasn’t verified this app’ choosing 'Go to home-assistant.io (unsafe)
  5. Grant access to the Google account
  6. Link to home assistant account
  7. Return to the integrations page and get this error: Unknown error talking to Cloud Pub/Sub, see logs

When I view the logs it says:

Logger: homeassistant.components.nest.config_flow
Source: components/nest/config_flow.py:265
integration: Google Nest (documentation, issues)
First occurred: 14 January 2025 at 16:45:25 (13 occurrences)
Last logged: 15:59:08

Error listing eligible Pub/Sub topics: Error while listing existing cloud console topics

Then as a separate error on the logs:

Logger: google_nest_sdm.admin_client
Source: runner.py:154
First occurred: 14 January 2025 at 16:45:25 (13 occurrences)
Last logged: 15:59:08

Unexpected error listing topics: Forbidden response from API (403): PERMISSION_DENIED (403): User not authorized to perform this action.

Does anyone know what might be causing this? I had wondered if it was because my Google Cloud Project was on a different Google account. I also read that I needed to create a topic in Google Cloud so have also done that, but no change.

Bit stuck here so any advice very welcome. Thanks.

Just recreated this on my personal google account and it worked so I think it was related to having the google cloud instance on a separate account.

A useful pointer:
On the integrations page click the three dots in top right corner and delete existing Google Nest credentials as the oauth details are saved. This resets the Nest creation process.

This was extremely helpful and helped me resolve the issue I had, for the past 3 weeks, to re-install Nest. Thanks !

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